Cut-out for electric circuits



UNITED STATES PATENT Erica.

MICHAEL LEAVY, OF PITTSFIELD, MASSACHUSETTS.

CUT-OUT FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 490,292, dated January24, 1893.

Application filed June 16, 1892. Serial No. 436,971. (No model.)

To all whom it may concern.

Be it known that I, MICHAEL LEAVY, a citizen of the United States,residing at Pittsfield, in the county of Berkshire and State ofMassachusetts, have invented certain new and useful Improvements inOut-Outs for Electric Circuits, of which the followingis aspecification, reference being had to the drawings accompanying andforming a part of the same.

This invention is an improvement in fusible or safety cut-out devicesfor electric circuits, which is designed to afford a more practicable,and safe device for this purpose than those in present use. I

The improvements reside mainly in a novel construction of the holder forthe fusible safety strip and in the means for including the same in thecircuit, and by means of which the strips may be inserted or replaced incase of fusion without the use of tools, and by which better protectionagainst the injury from the continuance of an arc is secured.

In the drawings hereto annexed I have illustrated in detailtheconstruction which constitutes my invention.

Figure 1 is a top plan view of a cut-out box or case with myimprovements applied thereto. Fig. 2 is a longitudinal vertical sectionon line 0c-0c of Fig. 1. Fig. 3 is a vertical cross section of a portionof the instrument on the line i y of Fig. 1.

The arrangement shown in the drawings is one more especially designedfor use with a main circuit, as for example a street line when it entersa building, but the invention is equally applicable to circuitsgenerally,wherever it is necessary or desirable to place a safetycut-out, as will be understood by those skilled in the art to which theinvention pertains.

I employ a box or casing A, of porcelain or other suitable insulatingmaterial, provided with a suitable cover B, andadapted to be secured toa wallor other support.

1n the particular form of device herein illustrated, are two copperblocks 0, D, at one end of the box provided with screws or clamps E, bymeans of which the line wires F are connected to them.

At the opposite end of the box are two other blocks II, I, also providedwith binding screws E, and to which the line wires running from the boxare connected. The interior of the box is preferably divided by aninsulating longitudinal partition G. The blocks 0, D, are bridged orconnected with the blocks H, I, through safety strips in the followingmanner: J, K, and J, K are copper blocks secured to the bottom or sidesof the box ata proper distance from the blocks H, I, and a switch isprovided for connecting either J and J or K and K with the blocks 0 andD respectively. A convenient device for this purpose is a slide L ofinsulating material carrying conducting cross-bars M, which by thetransverse movement of the slide are caused to pass under spring clampsor jaws N on the respective blocks. The object of this is that when onesafety strip or one set of the same fuses or becomes injured, thecontinuity of the line may be immediately re-established by shifting theslide and throwing in the other set, while the first are being replacedor repaired. Each block J, K, J, K is formed or provided with springjaws or clips 0, and a pair of similar clips is provided on each blockH, I. These are to receive the terminals of the safety strip holders.The

latter consist of tubes P of insulating and preferably refractory ornon-combustible ma terial, provided with metallic ends or ferrules R,closed at their ends except for a threaded hole for the insertion of aclamping screw S and a notch or opening T for the passage of a safetywire V. From the caps or ferrules extend lugs or wings W, which affordthe means of connecting the safety strips in circuit by forcing themdown between the spring jaws or clips 0. A safety or fusible wire orstrip slightly longer than the tubes is passed through the tube and itsprojecting ends bent over against the conducting ends of the tube. Thescrews S are then turned to bind the ends of the wire against the endsof the ferrules and make good electrical contact therewith so that whenthe tubes are set in position with the wings or lugsWbetween the springjaws O a perfect conducting bridge is formed through the safety stripsbetween the conducting blocks.

By the arrangement herein described one safety strip in each compartmentis kept in circuit by the slide switch.

In each tube P and at one or both ends of the same are openings X. Theseserve the very useful purpose of permitting the escape of air and gas onthe fusion of the safety wire within the tube, and thus create a draftby the confined air and gases rushing toward and through the openingsthat extinguishes the arc, which when the tube is practically closed orwhen no tube is employed is liable to form and destroy the apparatus.

I am aware that safety strip holders have been used with spring clampingdevices, and also that switch mechanism has been employed in conjunctionwith a number of safety strip terminals to bring one strip into circuitwhen another has blown out or fused, and these features I do not claim.

IVhat I claim is:

1. The combination of the insulating box or case, the line terminals 0,D and H, I, the conducting blocks J, J and K, K, the safety stripselectrically connecting the terminals H, I with said blocks, the slideL, the metallic cross-bars thereon, and spring clips on the terminals 0,D, and the blocks .1, J, K, K, respectively, with which said cross-barsare adapted to engage, as set forth.

2. The combination with an insulating safety stripholderhavingmetallicendsformed or provided with lugs or wings, and meansfor binding or clamping the ends of a safety strip to said metallicends, of terminals provided or formed with spring jaws or clips forreceiving the lugs or wings and thereby retaining the safety strip incircuit, as set forth.

3. The combination with an insulatingtube having metallic ferrules orends formed or provided with lugs or wings, and binding screws forclamping to the ferrules the ends of a safety strip contained within thetube, of metallic terminals provided with spring jaws or clips by whichthe lugs or wings on the metallic ferrule or ends of the safety tube areheld, as herein set forth.

4. The combination with the insulating tube, the end ferrules havingthreaded openings for the insertion of clamping screws and notches oropenings for the passage of a safety strip, and formed or provided withlugs or wings IV, of spring clips or jaws formin g circuit terminals andadapted to receive and hold the safety strip tube by engaging with thelugs on the ferrules of the same, as set forth.

5. In a safety strip holder, the combination of an insulating tubehaving air passages or openings at 01' near the ends, metallic ferrulesor ends formed with lugs or wings adapted for connection with terminalclips of the circuit, and having threaded openings for the passage of asafety-strip, and clam ping screws for binding the ends of saidsafety-strip to the ferrules, as set forth.

MICHAEL LEAVY.

Witnesses:

JOHN M. COLLINS, PARKER W. PAGE.

